1993 Toyota Paseo

I changed my air filter, oil filter, changed my oil, flushed my cooling system, flushed my brakes and power steering fluid, filled my gas tank and used stp complete fuel system cleaner, and changed my spark plugs and my car still stalls out.
What do you think can be the cause of my car stalling out?
I also changed my back lights and when I turn the lights on they don't go on and I changed the fuse.
What can be the cause of that?

Thank You!